An integrated model for simulating nitrogen trading in an agricultural catchment with complex hydrogeology

• Published in: Journal of environmental management Vol. 127; pp. 268 - 277
• Main Authors: Cox, T.J., Rutherford, J.C., Kerr, S.C., Smeaton, D.C., Palliser, C.C.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 30.09.2013; Elsevier; Academic Press Ltd
• Subjects: agricultural land; agricultural watersheds; Animal, plant and microbial ecology; Applied ecology; Biological and medical sciences; Conservation, protection and management of environment and wildlife; Earth sciences; Earth, ocean, space; econometric models; Economics; environmental markets; Exact sciences and technology; Fundamental and applied biological sciences. Psychology; General aspects; geophysics; groundwater; Groundwater - chemistry; Hydrogeology; Hydrology; Hydrology. Hydrogeology; Lakes; Lakes - chemistry; Leaching; mathematical models; Models, Theoretical; New Zealand; Nitrogen; Nitrogen - analysis; Nitrogen - chemistry; Numerical modeling; Runoff; Simulation; simulation models; Water Pollutants, Chemical - analysis; Water Pollutants, Chemical - chemistry; Water quality; Water quality trading; New Zealand; Rotorua New Zealand; Numerical modeling; Economics; Hydrology; Nitrogen; Water quality trading; Environmental management; Modeling; Trade; Hydrogeology; Agricultural region; Watershed; Water quality; Rural area; Numerical simulation; Economic aspect; Simulation model
• ISSN: 0301-4797; 1095-8630
• DOI: 10.1016/j.jenvman.2013.05.022

Nitrogen loads to several New Zealand lakes are dominated by nonpoint runoff from pastoral farmland which adversely affects lake water quality. A ‘cap and trade’ scheme is being considered to help meet targets set for nitrogen loads to Lake Rotorua, and a numerical model, NTRADER, has been developed to simulate and compare alternative schemes. NTRADER models both the geophysics of nitrogen generation and transport, including groundwater lag times, and the economics of ‘cap and trade’ schemes. It integrates the output from several existing models, including a farm-scale nitrogen leaching and abatement model, a farm-scale management economic model, and a catchment-scale nitrogen transport model. This paper details modeling methods and compares possible trading program design features for the Lake Rotorua catchment. Model simulations demonstrate how a cap and trade program could be used to effectively achieve challenging environmental goals in the targeted catchment. However, results also show that, due to complex hydrogeology, satisfactory environmental outcomes may be not achieved unless groundwater lag times are incorporated into the regulatory scheme. One way to do this, as demonstrated here, would be to explicitly include lag times in the cap and trade program. The utility of the model is further demonstrated by quantifying relative differences in abatement costs across potential regulatory schemes. •A numerical model (NTRADER) was developed to simulate a water quality trading market.•The model simulates fate and transport of nitrogen (N) in a catchment.•It also simulates the economics and regulatory structure options of an N trading program.•The model is used to compare trading program design options.•Results show consideration of hydrologic complexities is important in program design.